Tobacco curing apparatus

ABSTRACT

Tobacco curer for enclosed space having open top combustion chamber with heat exchanger housing surrounding and spaced therefrom. Horizontal top of housing connected to depending side wall with air inlet adjacent bottom of housing. Angularly spaced radial outlets in housing discharge but air and products of combustion. Conical hood spaced from top of housing provides continuous annular outlet which receives air under pressure from a blower through a central inlet in hood. The blower receives air from inside and outside the enclosed space and air discharged from annular outlet moves at greater velocity than air and products of combustion discharged from radial outlets.

United States Patent Dew [ 51 June 13,1972

[54] TOBACCO CURING APPARATUS Robert C. Dew, New Albany, Ind.

[73] Assignee: Stration & Terstegge Co., Inc.

[22] Filed: March 26, 1971 [2!] Appl. No.: 128,272

[72] Inventor:

[52] U.S. Cl. ..263/l9 D [51] Int. Cl ....F23l 9/04 [58] Field of Search ..263/1 9 [56] References Cited UNITED STATES PATENTS 2,569,084 9/ 195 1 White ..263/l9 D 3,367,643 2/1968 Copeland... ....263/19 D 3,437,323 4/1969 Thomas ..263/l9 D Primary Examiner-Edward G. Favors Attorney-Jennings. Carter & Thompson [57] ABSTRACT Tobacco curer for enclosed space having open top combustion chamber with heat exchanger housing surrounding and spaced therefrom. Horizontal top of housing connected to depending side wall with air inlet adjacent bottom of housing. Angularly spaced radial outlets in housing discharge but air and products of combustion. Conical hood spaced from top of housing provides continuous annular outlet which receives air under pressure from a blower through a central inlet in hood.

The blower receives air from inside and outside the enclosed space and air discharged from annular outlet moves at greater velocity than air and products of combustion discharged from radial outlets.

11 Claims, 2 Drawing Figures PATENTEnJuu 13 I972 3, 669,429

INVENTOR. Robert C Dew Attorneys TOBACCO CURING APPARATUS BACKGROUND OF THE INVENTION This invention relates to tobacco curing apparatus and more particularly to means for heating an enclosed space wherein a mixture of hot gaseous products of combustion and air are distributed throughout the enclosed space.

Heretofore in the art to which my invention relates, difficulties have been encountered in heating enclosed spaces for the curing of tobacco due to the fact that it is not only necessary to distribute the heated air throughout the entire enclosed area but the high temperature of the products of combustion must be reduced to a usable temperature to prevent damage to the tobacco being cured. Also, difficulties have been encountered due to the distortion of the metal structure forming conventional heaters due to the face that no effective means has been provided for reducing the elevated temperatures encountered near the top of the heat exchanger. Furthermore, difficulties have been encountered in thoroughly mixing the hot air and products of combustion with cooler air drawn into the heater whereby heated air can be distributed to all parts of the enclosed space at a uniform and even temperature. Still further difiiculties have been encountered in tobacco curing apparatus due to the fact that the heated air is often diverted downwardly onto the surrounding ground whereby the ground absorbs a portion of the heat generated, thus increasing the cost of fuel and at the same time increasing the curing time.

BRIEF SUMMARY OF THE INVENTION In accordance with my invention I provide a tobacco curer for an enclosed space which embodies an open top combustion chamber mounted within and spaced from a heat exchanger housing. The heat exchanger housing has a horizontal top connected to depending sides with air inlets adjacent the bottom of the housing and angularly spaced radial outlets in the upper portion of the housing which discharge hot air and products of combustion. A conical hood is mounted above and spaced from the top of the heat exchanger housing to provide a continuous, annular outlet which discharges air subjacent the entire periphery of the conical hood. A centrally disposed opening provided in the conical hood receives air from a blower unit which in turn receives air from inside and outside the enclosed space. The air is forced through the centrally disposed opening in the conical hood at a velocity to provide a plenum chamber between the conical hood and the top of the heat exchanger and force air outwardly through the continuous, annular outlet at a velocity greater than the velocity at which the hot gases and products of combustion are discharged from the angularly spaced radial outlets. The higher velocity air moving over the radial outlets from the heat exchanger causes the hot air and gases to be aspirated into the high velocity stream whereby the heated mixture is thoroughly intermixed and forced throughout the entire enclosed space. Also, as the cooler air moves into contact with the upper surface of the heat exchanger, heat is absorbed by this air whereby the heat exchanger structure is cooled to thus reduce distortion of the structure and at the same time supply heat to the air passing through the plenum chamber. Furthermore, the mixing of the hot and cold gases under the heat exchanger reduces the high temperature of the products of combustion to a useable temperature.

Apparatus embodying features of my invention is illustrated in the accompanying drawing, forming a part of this application, in which:

FIG.,1 is a vertical sectional view through my improved tobacco curer; and,

FIG. 2 is a viewtaken generally along the line 2-2 of FIG. 1 with the blower unit being removed.

Referring now to the drawing for a better understanding of my invention, 1 show an open top combustion chamber which communicates with a conventional type oil fired burner 11 by a conduit 12. The burner 11 may be of the conventional gun type heater. The heated products of combustion rise in the combustion chamber 10 and move outwardly of the upper end thereof as indicated by the arrows 13.

Surrounding and spaced from the combustion chamber 10 is a heat exchanger housing 14 which comprises a horizontal top wall 16 connected to a depending, continuous side wall 17 which terminates as at 18 to provide an air'inlet opening 19 between the lower portion of the heat exchanger housing 14 and the combustion chamber 10 whereby cool air is drawn inwardly around the combustion chamber 10, as indicated by the arrows 21.

Angularly spaced, radial outlets 22 communicate with the upper portion of the heat exchanger housing 14 in position'to discharge hot air and gaseous products of combustion. Mounted for pivotal movement in each of the outlets 22 is an adjustable baffle 23 for controlling the flow of hot air and gases therethrough. Each baffle member 23 is mounted on a shaft-like member 24 which extends through suitable openings provided in short cylindrical members 26 which surround the outlets 22. The lower end of each shaft-like member 24 projects outwardly of the cylindrical member 26 to provide a control handle 27 whereby the baffle 23 may be rotated to selected positions.

Mounted above the top wall 16 of the heat exchanger housing 14 is a conical hood 28 having a convex upper surface 29 and a concave under surface 31, as shown in FIG. 1. The hood 28 is supported by angularly spaced support brackets 32 which are interposed between the upper surface of the heat exchanger 14 and the under, concave surface of the hood. The support brackets 32 are of a height to support the lower edge 33 of the conical hood 28 at an elevation ranging from a inch to 2 inches above the upper, horizontal surface of the top wall 16. Preferably, the lower edge 33 of the conical hood 28 is supported approximately 1 inch above a plane passing through the upper surface of the top wall 16.

As shown in FIGS. 1 and 2, a centrally disposed opening 34 is provided in the conical hood 28. Mounted-on top of the conical hood 28and communicating with the opening 34 is a cylindrical housing 36 for a blower unit indicated generally at 37. Mounted within the cylindrical housing 36 on a suitable supporting structure 38 is a fan unit 39 which is driven in a direction to force air downwardly onto the upper surface of the top wall 16, as indicated by the arrows 41.

As shown in FIG. 1, the lower portion of the cylindrical housing 36 is imperforate while the upper portion thereof is perforated or provided with an open mesh structure, such as hardware cloth 42, whereby air may be drawn inwardly of the blower unit. The upper end of the cylindrical housing 36 communicates with one end of an inlet conduit 43. The other end of the inlet conduit 43 extends outwardly of the enclosed area which surrounds the tobacco curing apparatus whereby fresh air, at ambient temperature, is drawn from outside the curing room. As shown in FIG. 1, the conduit 43 is connected to a conical cover member 44 which is secured to the upper end of the cylindrical housing 36. A suitable control baffle 45 is mounted for pivotal movement in the conduit 43 for regulating the amount of air introduced therethrough. For example where the outside air is below a predetermined temperature, the bafile 45 is moved toward closed position to restrain the flow of air.

From the foregoing description, the operation of my improved tobacco curing apparatus will be readily understood. The apparatus is mounted within an enclosed space, such as a tobacco curing room, and the'bumer unit 11 is energized whereby the heated products of combustion move upwardly in the direction of the arrows 13 into the heat exchanger housing. As the hot gases of combustion rise and come in contact with the under surface of the top wall 16, mixing by natural convection takes place with the products of combustion and cool air which is drawn in through the opening 19 around the combustion chamber 10. The mixing of the hot and cold gases beneath the top wall 16 of the heat exchanger housing reduces the high temperature of the products of combustion to a useable temperature before the gases are discharged horizontally through the outlets 22 in the direction of the arrows 46. Accordingly, the thorough mixing of the hot gases and the cool air not only cools the products of combustion to a useable temperature but also prevents distortion of the metal components of the heat exchanger structure. It is very desirable that the gases discharged through the outlets 22 be below a predetermined temperature due to the fact that heated gases within high temperature ranges are damaging to the tobacco which is supported in the enclosed space in a manner well understood in the art to which my invention relates.

Since the top of the heat exchanger 14 is in the form of a flat, circular surface, the heated gases rise and contact this flat surface whereby the gases are discharged through the outlets 22 in a relatively smooth pattern and at a low velocity by convection forces.

The fan unit 39 of the blower 37 is driven at a speed to force air downwardly through the space defined between the upper surface of the heat exchanger 14 and the under surface of the conical hood 28 at a much greater velocity than the velocity at which the heated gases are discharged from the outlets 22 to thus provide a plenum chamber between the heat exchanger and the hood 28. As the higher velocity air moves over the heat exchanger outlets 22, the hot gases moving in the direction of the arrows 46 are aspirated into the high velocity air stream moving in the direction of the arrows 47 whereby the heated air mixture is forced throughout the entire enclosed space surrounding the tobacco curing apparatus. The angularly spaced brackets 32 are relatively narrow in width whereby they do not interfere with the movement of the air through the plenum chamber defined between the heat exchanger and the conical hood. Accordingly, an annular, continuous passageway is provided between the upper edge of the heat exchanger housing 14 and the under edge of the conical hood 28 whereby air is forced outwardly in the direction of the arrows 47 around the entire periphery of the conical hood. Accordingly, the air delivered by the fan unit 39 is forced downwardly on top of the heat exchanger 14 whereby the fiat top 16 diverts the air so that it moves radially into a horizontal plane beneath the entire periphery of the hood 28. The air then moves outwardly in the direction of the arrows 47 I whereupon the hot gases moving in the direction of the arrows 46 are aspirated into the high velocity air stream.

As the blower unit 37 operates, air is drawn inwardly through the open mesh surface 42 and at the same time is drawn inwardly through the conduit 43 whereby air is supplied both from outside the enclosed space and from within the enclosed space surrounding the apparatus, such as the tobacco drying room or barn. The ambient air drawn from outside of the building flows over the motor for the fan unit 39 thus dissipating heat from the motor. A suitable high temperature cut off switch or thermostat 48 is mounted on the conical cover member 44, as shown.

From the foregoing it will be seen that l have devised improved tobacco curing apparatus which not only protects the structural components of the heat exchanger from damage due to overheat but also assures uniform and thorough mixing of the hot gases with the cooler air whereby the mixture of hot gases and air, at a uniform temperature, are forced throughout the enclosed area surrounding the apparatus. By forcing the air downwardly onto the top of the horizontal wall 16 of the heat exchanger and then outwardly beneath the hood 28 at a velocity substantially greater than the velocity at which the heated gases and air are discharged from the heat exchanger, the heated gases and air are aspirated into the higher velocity gases moving thereover to thus thoroughly mix the gases with the cooler air. By thus mixing the hot gases with the cooler air discharged from the annular space subjacent the lower edge of the conical hood 28, I not only bring about a uniform temperature of the mixture, but also bring about a uniform flow of the mixture throughout the entire enclosed space surrounding the apparatus.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is: 1. In tobacco curing apparatus for supplying heated air to an enclosed space within which said apparatus is located,

a. an open top combustion chamber having fuel. supply means communicating therewith,

b. a heat exchanger housing surrounding and spaced from said combustion chamber and having a horizontal top wall connected to a depending side wall,

c. air inlet means adjacent the bottom of said heat exchanger housing,

angularly spaced radial outlets communicating with the upper portion of said heat exchanger housing discharging hot air and gaseous products of combustion from said heat exchanger housing into said enclosed space, a conical hood supported in spaced relation to the top of said heat exchanger housing with the upper surface of said hood being convex and the under surface thereof being concave and defining a substantially continuous, annular outlet between the upper edges of said heat exchanger housing and the under surface of said hood disposed above said radial outlets,

a centrally disposed air inlet passageway through said conical hood,

a blower unit mounted above and communicating with said centrally disposed air inlet passageway forcing air downwardly onto said horizontal top wall and then outwardly through said annular outlet providing a plenum chamber between said top wall and said conical hood,

means forcing air through said blower unit at a velocity to move air at a greater velocity through said annular outlet than the velocity at which the hot air and gaseous products of combustion are discharged through said radial outlets so that the hot air and gaseous products of combustion are aspirated into the higher velocity air discharged through said annular outlet to produce a heated mixture which is forced throughout said enclosed space, and

i means supplying air to said blower unit.

2. Tobacco curing apparatus as definedin claim 1 in which adjustable baffles are mounted for pivotal movement in each said radial outlet for controlling the flow of air therethrough.

3. Tobacco curing apparatus as defined in claim 1 in which the air inlet means adjacent the bottom of said heat exchanger housing extends substantially the entire distance around said heat exchanger housing. Y

4. Tobacco curing apparatus as defined in claim 1 in which said depending side wall is cylindrical.

5. Tobacco curing apparatus as defined in claim 1 in which the lower edge of said conical hood is spaced from approximately one-half inch to 2 inches above said horizontal top wall.

8. Tobacco curing apparatus as defined in claim 1 in which at least a portion of the air supplied to said blower unit is supplied by a conduit communicating at one end with said blower unit with the other end of said conduit receiving ambient air outwardly of said enclosed space.

9. Tobacco curing apparatus as defined in claim 1 in which said blower unit comprises a rotary fan unit mounted in a cylindrical housing.

10. Tobacco curing apparatus as defined in claim 9 in which air inlet passageways are provided through said cylindrical housing for receiving air directly from said enclosed space and one end of a conduit communicates .with said cylindrical housing with the other end of said conduit receiving air from a lo- 6. Tobacco curing apparatus as defined in claim 1 in which cation outwardly of said enclosed space whereby air is supplied from both outside and inside said enclosed space.

11. Tobacco curing apparatus as defined in claim in which an adjustable baffle member is mounted within said conduit which receives air from a location outwardly of said 5 enclosed space whereby the flow of air therethrough is controllable. 

1. In tobacco curing apparatus for supplying heated air to an enclosed space within which said apparatus is located, a. an open top combustion chamber having fuel supply means communicating therewith, b. a heat exchanger housing surrounding and spaced from said combustion chamber and having a horizontal top wall connected to a depending side wall, c. air inlet means adjacent the bottom of said heat exchanger housing, d. angularly spaced radial outlets communicating with the upper portion of said heat exchanger housing discharging hot air and gaseous products of combustion from said heat exchanger housing into said enclosed space, e. a conical hood supported in spaced relation to the top of said heat exchanger housing with the upper surface of said hood being convex and the under surface thereof being concave and defining a substantially continuous, annular outlet between the upper edges of said heat exchanger housing and the under surface of said hood disposed above said radial outlets, f. a centrally disposed air inlet passageway through said conical hood, g. a blower unit mounted above and communicating with said centrally disposed air inlet passageway forcing air downwardly onto said horizontal top wall and then outwardly through said annular outlet providing a plenum chamber between said top wall and said conical hood, h. means forcing air through said blower unit at a velocity to move air at a greater velocity through said annular outlet than the velocity at which the hot air and gaseous products of combustion are discharged through said radial outlets so that the hot air and gaseous products of combustion are aspirated into the higher velocity air discharged through said annular outlet to produce a heated mixture which is forced throughout said enclosed space, and i means supplying air to said blower unit.
 2. Tobacco curing apparatus as defined in claim 1 in which adjustable baffles are mounted for pivotal movement in each said radial outlet for controlling the flow of air therethrough.
 3. Tobacco curing apparatus as defined in claim 1 in which the air inlet means adjacent the bottom of said heat exchanger housing extends substantially the entire distance around said heat exchanger housing.
 4. TobaccO curing apparatus as defined in claim 1 in which said depending side wall is cylindrical.
 5. Tobacco curing apparatus as defined in claim 1 in which the lower edge of said conical hood is spaced from approximately one-half inch to 2 inches above said horizontal top wall.
 6. Tobacco curing apparatus as defined in claim 1 in which the lower edge of said conical hood is spaced one inch above said horizontal top wall.
 7. Tobacco curing apparatus as defined in claim 1 in which said conical hood is supported by angularly spaced support brackets mounted between said horizontal top wall and the under surface of said conical hood.
 8. Tobacco curing apparatus as defined in claim 1 in which at least a portion of the air supplied to said blower unit is supplied by a conduit communicating at one end with said blower unit with the other end of said conduit receiving ambient air outwardly of said enclosed space.
 9. Tobacco curing apparatus as defined in claim 1 in which said blower unit comprises a rotary fan unit mounted in a cylindrical housing.
 10. Tobacco curing apparatus as defined in claim 9 in which air inlet passageways are provided through said cylindrical housing for receiving air directly from said enclosed space and one end of a conduit communicates with said cylindrical housing with the other end of said conduit receiving air from a location outwardly of said enclosed space whereby air is supplied from both outside and inside said enclosed space.
 11. Tobacco curing apparatus as defined in claim 10 in which an adjustable baffle member is mounted within said conduit which receives air from a location outwardly of said enclosed space whereby the flow of air therethrough is controllable. 